Mercurial > gui
annotate changePoller.ur @ 14:0827320b0f04
Write calendarCtl in terms of a source with a listener.
| author | Karn Kallio <kkallio@eka> |
|---|---|
| date | Fri, 05 Aug 2011 18:55:24 -0430 |
| parents | |
| children |
| rev | line source |
|---|---|
| kkallio@14 | 1 con changePoller t = {Val : source t, |
| kkallio@14 | 2 Last : source t} |
| kkallio@14 | 3 |
| kkallio@14 | 4 fun create [t ::: Type] (_ : eq t) (i : t) = |
| kkallio@14 | 5 v <- source i; |
| kkallio@14 | 6 l <- source i; |
| kkallio@14 | 7 |
| kkallio@14 | 8 return {Val = v, |
| kkallio@14 | 9 Last = l} |
| kkallio@14 | 10 |
| kkallio@14 | 11 fun addChangeListener [t ::: Type] (_ : eq t) f pollInterval cp = |
| kkallio@14 | 12 let |
| kkallio@14 | 13 fun go () = |
| kkallio@14 | 14 sleep pollInterval; |
| kkallio@14 | 15 sample <- get cp.Val; |
| kkallio@14 | 16 lst <- get cp.Last; |
| kkallio@14 | 17 if sample = lst then |
| kkallio@14 | 18 go () |
| kkallio@14 | 19 else |
| kkallio@14 | 20 f sample; |
| kkallio@14 | 21 set cp.Last sample; |
| kkallio@14 | 22 go () |
| kkallio@14 | 23 in |
| kkallio@14 | 24 go () |
| kkallio@14 | 25 end |
| kkallio@14 | 26 |
| kkallio@14 | 27 fun ctl [t ::: Type] cp = cp.Val |
| kkallio@14 | 28 |
| kkallio@14 | 29 fun value [t ::: Type] cp = signal (cp.Val) |
| kkallio@14 | 30 |